I'm looking for a commuter that I can ride problem free for ~2-4 years. The LBS in my area are having sales on '06 models and I've been thinking about purchasing a road bike as a commuter. Some of the choices are:

I think I've read somewhere that the more expensive components, although lighter, are less durable. Is this true? Overall, would these bikes serve well as a commuter? My route is 6 miles of well paved road in Northern VA suburbs. I do have a MTB for the really bad days; however, I'd still like to ride a road bike during light rain...is a fender out of the question for the above bikes?

Any of those bikes will be reliable/durable for years. They'll all come with STI (brifters)....I'd try to find something with 105 level stuff (allez elite) just in case you like to ride for fun. Even the low end components are solid if that's all you need...just pick one you like.

I'm looking for a commuter that I can ride problem free for ~2-4 years. The LBS in my area are having sales on '06 models and I've been thinking about purchasing a road bike as a commuter. Some of the choices are:

Have you considered a 'cross bike, rather than a traditional racing-oriented road bike? Cross bikes are easier to fit with racks, fenders, and wide tires... and usually slightly less geometry, but can offer the advantages of integrated shifting, aerodynamic body position, and light weight of other road bikes.

I am a big fan of the Bianchi Volpe (about $900, steel, with Tiagra brifters) and the Surly Cross Check (similar).

I am also a DC area commuter! I currently live in NE DC and commute to College Park, MD. I use my homebuilt steel road/touring bike.

All those bikes are good. I have the Specialized Allez Sport, which I ride when I'm not on my other bike. I like it just fine. You can get a clip-on rear fender that attaches to the seatpost. It's not as good as full fenders with mudflaps, but they're much better than nothing.

And you'll probably be a bit faster on your road bike than you are on your MTB.

Have you considered a 'cross bike, rather than a traditional racing-oriented road bike? Cross bikes are easier to fit with racks, fenders, and wide tires... and usually slightly less geometry, but can offer the advantages of integrated shifting, aerodynamic body position, and light weight of other road bikes.

If you are considering a Specialized, maybe the Tricross Sport fits in your budget...

I am a big fan of the Bianchi Volpe (about $900, steel, with Tiagra brifters) and the Surly Cross Check (similar).

I am also a DC area commuter! I currently live in NE DC and commute to College Park, MD. I use my homebuilt steel road/touring bike.

I was actually looking at the Volpe after reading some posts about its versatility. The only thing that put me off is the weight. The website doesn't list how much it weighs. Unfortunately, I have quite the flight of stairs in my complex. They're old fashioned apartment building style with the ultra steep angle. It's doable - I carry my lead weight MTB - but a big inconvenience at 3:00 in the morning after school and work.

I was actually looking at the Volpe after reading some posts about its versatility. The only thing that put me off is the weight. The website doesn't list how much it weighs. Unfortunately, I have quite the flight of stairs in my complex. They're old fashioned apartment building style with the ultra steep angle. It's doable - I carry my lead weight MTB - but a big inconvenience at 3:00 in the morning after school and work.

If that's not light enough for you, then you should probably consider an aluminum cross bike, with carbon fork. That should be several pounds lighter than a similar steel bike. I'm afraid I don't have any knowledge of any of those, hopefully someone else should chime in.

A leftover jamis nova ('06) is steel with full 105 and weighs ~22 lbs and goes for $1k....it has braze ons and is just a SWEET bike overall. Also consider the surly crosscheck and long haul trucker, and the volpe is a good bike too.

Thanks for all the helpful comments. Jamis and Surly weren't even options I thought of. And 22lbs is definitely something I can do with. I think I'm gonna go check out an '06 Nova leftover near me. Slightly above my budget at 1049.99 but they'll have to work with me on the price!

Of the bikes I originally listed...are the 105 components (F80 and Elite Triple) worth the extra 200-300 over the Tiagra components? Especially if it's mostly for commuting.

Thanks for all the helpful comments. Jamis and Surly weren't even options I thought of. And 22lbs is definitely something I can do with. I think I'm gonna go check out an '06 Nova leftover near me. Slightly above my budget at 1049.99 but they'll have to work with me on the price!

Of the bikes I originally listed...are the 105 components (F80 and Elite Triple) worth the extra 200-300 over the Tiagra components? Especially if it's mostly for commuting.

I would say that $200-300 extra for 105 components is questionably worth it for commuting use... you get 10-speed (which means your chains will wear out faster ), total weight loss of a few hundred grams, and brake levers that are made of metal instead of plastic. For that extra money, you'll probably ALSO be getting a slightly better wheelset, better quality frame and fork, etc.

If you can deal with 22 lbs then take a few steel bikes for a spin, you'll not regret it

Most race bikes have little clearance for wider tyres + fenders. You could probably squeeze raceblades over 23mm rubber. If you want 25/28mm tyres + proper bolt-on fenders you should look at frames which place the brake blocks at the bottom of std calipers or look for one that is designed for long drop caliper brakes; these can take 32mm+ fenders.
Surly, Soma and Gunar all do a club style road bike with long drops calipers.